leitner and w



H. LEITNER AND W H. EXLEY.

ELECTRIC ACCUMULATOR PLATE.

APPLICATION FILED DEC 16 l9l8.

Patented June 3, 1919.

2 SHEETS-SHEET I H. LEITNER AND W. H. EXLEY.

ELECTRIC ACCUMULATOR PLATE. APFHCATIDN FILED DEC-15.1918.

Patented .kune 3, 1919.

ZSHEETS4SHEIETZ. a

HENRY LEITNER, F .VESTMINSTER, LONDON, AND WILLIAM HERBERT EXLEY, 0F WOKING, ENGLAND.

ELECTBIC-ACCUIiEULATOR PLATE.

Specification of Letters Patent.

Patented June 3, 191$.

Application filed December 16, 1918. Serial No. 266,982.

To all whom it may concern:

Be it known that We, HENRY LErrNER and VVILLIAM HERBERT EXLEY, subjects of the King of Great Britain, respectively residlng at 3 Victoria street, Westminster, London, England, and The Rest, Maybu ry Hill, JVoking, Surrey, England, have invented new and useful Improvements in Electrlo Accumulator Plates, of which the following is a specification.

Our invention relates to improvements n plates or elements of electric accumulators, of the kind in which lead cores and active material are supper upon a frame of Wood. The invention relates more particularly to the lead sulfuric acid bipolar type of plate described in our British specification No. 112956, but the improvements are not confined to plates of type.

The object, of the invention to prov de plates or elements having greater rigidity than the plates or elements heretotore known and also to provide a better contact. between the available active material and the lead. conductors without appreciably increasing the Weight 01 the latter. By these improve ments a lighter, cheaper, non-buchlmg, non, shortening and rigid element or plate of the bipolar ype is obtained, and one which is more suitable for hi h discharge work, which, as is Well lillfi requires thinner plates than those useo. for low discharge work.

in the accompanying drawings Figure l is an elevation of one form of plate or element having our improvements applied thereto.

Fig. 2 is an edge view thereof.

Fig. 3 is a vertical section on the line 33, Fig. 1.

Fig. ii is an elevatimi oi the parts of the wood support.

Fig. 5 is a view at right angles to Fig. l.

Fig. (l is a plan view oi the transverse bottom piece of the. support of the plate or element; and

Figs. 7 and 8 are an elevation and aplan, respectively, of a modified form oi end piece.

Fig. 9 is an elevation of a modified form of support.

Fig. 10 is a plan view thereof.

Fig. 11 is a vertical section on the line 1ll1, Pi 9.

Fig. 12 is a horizontal section on the line 12-12 Fig. 9.

Fig. 13 is a view of a detail hereinafter, described.

Fig. 1% is an elevation of a portion of a further modified form of support.

F ig. 15 is a sectional elevation illustrating a further modification.

Fig. 16 is an end view thereof.

Figs. 16*, 16 and 16 are an elevation, a vertical section and a horizontal section re spectively of a modification.

Fig. 17 is a horizontal section illustrating a further detail.

Fig. 18 is a vertical section showing a still further detail of construction; and,

Figs. 18 and 18 are an elevation and a horizontal section of a modification.

Figs. 19, 2G and 21 are an elevation, a plan view and a cross section respectively illustrating the application of the invention to a cell designed for use in torches, hand-lamps and the like.

lin one term of our invention as shown in l 1 to 6 (5 represents the support for the conductors and the active material. This support is of wood of a porous nature, which prior to the application ofthe conductors and ,active material, is renderedinore absorbent, porous and of a spongy resilience,

by being treated, for example, in solutions of hypochlorites and then with dilute sulfuric acid. The support may also he treated with a solution of caustic soda, or potash it found expedient, and this treatment in addi tion to making the wood more porous, as aforesaid, also extracts all deleterious substances therefrom. The said support is provided with a series of vertical grooves 5 upon either taco ot' a central web 6 which latter, together with t e veitical divisions (l between the grooves. are made as thin as practicable. The vertical divisions (Z extend beyond the ends of the web 0 andare provided with grooves c cut horizontally across the top and bottom of the support. and these grooves are preferably a little wider than the central web c. The bottoms of the gmovcs are spaced awa from the ends of thc central web 6. as own at f, and in the web 0 hot ween opposite grooves 7) are a series of holes 5 pretcraliljv corresponding in diameter a 'iroximately to the width of a groove.

timepieces 1 of wood are notched. at h to mesh in with the divisions d of the support, and these cross-pieces are inserted into the horizontal grooves e. The notches k are preferably a little wider than the divisions so as to permit a certain amount of lateral movement. This movement is due to the stretching of the wood fiber and expansion of active material. The notched connection of the divisions (l and cross-pieces It prevents undue lateral movement of the support and also prevents any leakage of active material from one side of the support to the other.

The top cross-piece h is provided on opposite sides with rabbets or saw cuts iof a depth and width corresponding to the di- Inensions of the collector bars 7' of the positive and negative conductors. The said colnector-bars, although they cross the tops of the groov s of opposite polarity, are insulated from the active material in these grooves by means of the ledges formed by the rabbets i.

The collector bars j are united to conductors 7c and terminal lugs Z, and these parts are preferably stamped, pressed, cut or formed from a sheet or other suitable piece of lead, in such a way, that depending from each collector bar there are a suitable number of streamers 70. These latter are flattened or otherwise reduced in thickness and twisted into a spiral form for the portion of their lengths which is in contact with the active material, the result being, that in-, creased contact surface is available for the same weight of lead and a stronger connection may be made with the active material. The streamers It" hang in the grooves b, half of the positive streamers extending under the top cross piece it and down the negative collector bar sideof the central web 0, and half the negative streamers extend under the top cross-piece and down the positive collector bar side of the web so that each pair of oppositely disposed grooves has either two positive streamers or two negative streamers, as clearly shown in Fig. 3. The free ends of the streamers may be secured by being bent through the space it" between the central web and the bottom cross-piece, as shown in Figs. 1 and 3.

The streamers may be given any additional shape or pat-tern such as the herring bone, all with the object of further increasing or rendering more effective the available surface. The streamers k may also be perforated if desired.

The active material m surrounds the streamers la and is held in position in the grooves 7) by the twisted streamers 7c and by interlocking with the large holes in the central web 0.

The streamers instead of being made from the same piece as the collector bars may be formed separately therefrom. For

instance, they may be composed of round wire flattened and twisted and afterward welded or otherwise secured to the collector bars 51', preferably before the latter are mounted upon the support.

In the modification illustrated in Figs. 9 to 16 the support is built up of a series of vertical strips of wood (Z held together by notched cross-strips n having notches n engaging the vertical strips. here necessary, as would be the case in a long late or element, additional cross pieces 0 ig. ll) may be furnished. This may be inserted transversely through holes in the vertical strips (Z at the requisite intervals, suitable collars or distance pieces being arranged around the said cross-piece as shown at p.

or through the cross-piece as illustrated at g.

Alternatively the cross-piece may be in two parts viz., a notched part 0 (Fig. 15) and the Plain part 0 of the holes in the vertical strips being big enough to allow the notched pieces to be inserted, after which the plain pieces are wedged in place to secure the notched pieces in position.

The vertical strips in this form of our invention may be of any convenient cross section preferably a double T or cross shape as shown in Figs. 9, l2 and 14, the said strips being cut away wherever the transverse cross pieces are inserted and the result being that the active material is held in position by both the cross strips and the central iniward projections on the vertical pieces, as well as the twisted streamers L. It will be understood that in this latter form of our invention, the stretching or lateral expansion of the support as a whole is practically eliminated as the grain of the wood in the transverse cross-piece is at right angles to the grain of the wood in the vertical strips, and as the latter are entirely separate units their expansion is local only and readily kept within practical limits by the transverse cross-pieces, which latter are an additional safe-guard against undue lateral expansion.

In lieu of the twisted streamer form of conductor above described, we may make use of a number of grid-like streamers depending from the common collector bars, hese streamers being pressed or stamped to orm a series of horizontal bars in", half of such horizontal bars being pressed in one direction and the other half being pressed in the opposite direction, as clearly shown in Figs. 16 16 and 16 The portion of the grid covered by the active material is reduced in thickness while the exposed portion is left normal.

lVith this construction, the grid-like streamers have their free or bottom ends secured to the bottom cross-piece by being inserted in recesses lu Figs. 9 and 11.

In both the aforementioned forms of our invention, we may make the bottom crosspiece of the same width as the divisions d as shown at h in Figs. 7 and 8, and if desired, we may taper the lower portion of the edges of the divisions d and the lower portion of the faces of the bottom cross-piece, as shown in Fig. 11. We may also make the top cross-piece of the same width as the divisions d in order to fill up the entire top ends of the vertical grooves with the exception of the spaces necessary to allow the positive and negative conductors to pass. The crosspiece at is shown detached, Fig. 13. The spaces which are left unfilled by the conductors may be closed by suitable plugs.

The strips 01 may, as shown in Fig. 17, be made thinner in cross section at the middle than at the edges so that when the strips are assembled to form a plate, the cross section of the space formed between each pair of adjacent strips is of the undercut shape, that is to say,'is larger at the center than at the two faces. By this means the active material, when it is compressed into position on the plate, is effectually held independently of any-lock or grip which may arise from the shape of the conductors in which the said active material is embedded.

Furthermore, we may curve or under-cut the inward faces of the top and bottom cross-pieces of the support as shown at 1" in Fig. 18, in such a manner that the space formed by them in vertical section is larger at the center than at the two faces, thus imparting an additional locking effectto the active material independently of the cond'uctors is.

In some cases, for example, with large plate elements, it may be advisable to make use of a composite support in which the top and bottom cross-pieces, together with the two end strips, are composed of ebonite, celluloid, impregnated teak or other suitaable acid resisting material of greater me chanical strength than porous wood, the dividing strips, however, being made of the porous wood.

Furthermore, in practice we find it advantageous to make the vertical strips d of the support widerthan is actually necessary to hold the active material, as illustrated in Fig. 17, so that when the said strips are assembled to form a support they project laterally beyond the active material, and then act as separators. With this construction, the outer edges of adjacent vertical strips approach each other so that each strip of active material is to all intents and purposes boxed in, whereby any portion of such material which may become dislodged cannot cause a short circuit between neighboring strips.

Free circulation of the electrolyte can be still further insured by cross-cutting the vertical strips with saw cuts or notches d extending to, or nearly to, the active mate rial, as shown in Figs. 18* and 18.

Figs. 19, 20 and 21 show the application. of the invention to a cell such as is used in connection with torches or the like. In this construction the support is preferably made with notches 8 at each end and strips of wood t are forced into the said notches, these strips being the equivalent of the end cross-pieces h and it above described. In this case the positive and negative terminal lugs u, u are situated at opposite ends of the support.

Claims:

1. In a plate or element for an electric accumulator, a support comprising a series of strips of porous wood having grooves between the same, active material located in said grooves, conductors embedded in said active material, and end pieces having notches engaging said strips, said notches being wider than the thickness of said strips to permit expansion and contraction of the support and active material.

2. .A plate as defined in claim 1, in which the strips are thinner at the middle than at the edges, and the end pieces are formed with curved under faces for locking the active material in the grooves.

3. A plate as defined in claim 1, in wljlich one of the end pieces is provided wit a rabbet, a collector bar engaging said rabbet, and a series of conductors carried by the collector bar and located in said grooves.

4. A plate as defined in claim 1, in which the edges of the strips project beyond the active material, so as to entirely isolate the material in one groove from the active material in an adjacent groove.

5. An element for electric accumulators comprising a non-conducting support including spaced strips, notched cross-pieces having their notches engaging the strips for securing the strips together, active material located in the space between said strips, and conductors embedded in said active material.

6. The combination with a grooved support having a space near its upper edge, of

a collector bar located in one side of said" tors.

HENRY LEITN ER. WILLIAM HERBERT EXLEY. 

